Socket insert



FIG. 1 is a front perspective view of a socket insert showing my new design;

FIG. 2 is a top view thereof, the bottom view being a mirror image thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a perspective view showing the socket insert in the environment in which it is to be used; and,

FIG. 6 is an alternative perspective view showing the socket insert in the environment in which it is to be used.

The broken lines showing environment is included for the purpose of illustrating the socket insert in use and forms no part of the claimed design. 

The ornamental design for a socket insert, as shown and described. 